Washing-machine

ABSTRACT

In connection with a machine for the treatment of laundry, in particular a washing-machine or drier, comprising weight sensors for automatic measurements of the weight of the laundry and subsequent determination of the quantities of treatment agents to be filled in (water, detergents, or the like), for determining the relative humidity content, for detecting and removing imbalance conditions, it is proposed to arrange a decoupling frame between an outer housing resting on a stationary supporting surface, and the entire inner system of the washing-machine or dryer, including the lye tank with drum and other partial components, the decoupling frame being itself resiliently suspended in the outer housing and supporting all the other components, and to provide weight sensors, preferable resistance strain gauges, which coact with the resilient suspension of the decoupling frame.

BACKGROUND OF THE INVENTION

The present invention relates to a machine for the treatment of laundry,such as a dryer or washing-machine.

A known washing-machine of this kind (DE-PS 30 25 088) has the drumsupported for rotation in the lye tank, while the lye tank is supportedin a suitable manner on the bottom of the housing, via resilient and, incertain cases, damping supports. The drum is supported in the lye tankin the usual manner, namely in unilaterally overhung arrangement, bymeans of a star-shaped mounting bracket fastened undetachably to theback of the lye tank by means of a plurality of screws and fishplates.The arms of the star-shaped mounting bracket extend right to theperipheral areas of the lye tank, and may even reach around the latter,for improved solidity, as the drum, being heavily loaded with wetlaundry in the operating condition of the machine, has a pronouncedtendency to tilt in the hub area of the star-shaped mounting bracketwhere it is held by only one double bearing.

In order to provide such a mechanical arrangement with a suitablemeasuring system which on the one hand permits the increasing weightcaused by the laundry being filled in to be recorded and evaluatedautomatically and which on the other hand operates with sufficientaccuracy, electromechanical transducers are arranged on those parts ofthe star-shaped mounting brackets which are exposed to particularlypronounced stresses under the effect of the drum weight. Theweight-proportional output signals supplied by these electromagnetictransducers, for example resistance strain gauges or piezoelectrictransducers mounted firmly in the material of the star-shaped mountingbracket, are then transmitted to a signal-processing arrangement whichis thereby enabled, for example, to evaluate the weight of the laundryfilled in and to derive therefrom automatically the liquid level in thelye tank and to adapt it as required.

This publication (DE-PS 30 25 088) clearly recognizes, and explains withreference to other publications likewise dealing with the problem ofrecording the weight of laundry (U.S. Pat. No. 2,412,270; DE-AS 11 57578; DE-OS 20 34 847) that sufficient accuracy, initially only withrespect to the weight of the laundry, can be achieved only under certainparticular conditions. The problems connected with the determination ofthe weight have been seen heretofore in the fact that, regardless of thetype of measuring sensor used, the dead weight of the washing machine(for example 100 Kg) makes it impossible for the usual increase inweight resulting from the dry laundry (approx. 0.5 to 5 Kg) to causeeffects important enough for being determined with sufficient accuracyfor use in an automatic control circuit.

In setting out this theory, DE-PS 30 25 088 disregards, however, atleast in part the main reason for the measuring inaccuracies namely thatall measuring processes previously employed are affected by excessivefrictional influences so that these, and the hysteresis produced by suchfrictional influences, are already sufficient reason that no exactresults can be expected for the desired weight measurements. While suchaccuracies are already critical in determining the weight of thelaundry, and the water level to be derived therefrom, they make suchmeasurements absolutely useless if one tries to determine automaticallythe quantity of detergents to be added, including the quantities offabric softeners, special detergents, and so on, and to use for thispurpose automatic control circuits, including in particularminicomputers and microprocessors with corresponding storage capacities,and the like, which are currently in use today, and this although suchprogram-controlled operation would be so very important today,especially under the aspects of environmental protection.

The same is true for the solution proposed by DE-PS 30 25 088 which doesnot itself even expect a better accuracy than a resolution of approx.0.1 Kg (column 3, line 4, of the quoted patent specification).

However, such measuring inaccuracies can by no means be accepted indetermining the quantities of detergents to be added, as in this case anaccuracy in the gram range would be required because in the case of apredetermined detergent quantity of 20 gram an extra of only 5 gramwould already mean that the prescribed quantity has been exceeded by25%.

This is in fact the reason why all solutions proposed heretofore,including the solutions contained in DE-OS 34 13 967, GB-2 087 438 A andEP 0294014 A1, cannot achieve acceptable results in practicalapplication although the addition of detergent quantities has beendiscussed in most of these publications, and program sequences andfully-automatic program controls have in fact been proposed in thisconnection for different operations, including the addition of detergentquantities adapted to the weight of the laundry.

It should be noted, however, in this connection that the drum-typewashing-machine disclosed by DE-OS 34 13 967 only had for its purpose toensure that the quantity of laundry filled into the washing-machineactually corresponds to the capacity of the drum, i.e. to avoid errorsthat may result from a mere estimation of the weight of the laundry andwhich may lead to the drum being either not used to full capacity orbeing overloaded in which case the laundry will not be cleaned asthoroughly as desired. In order to simplify the step of determining thecorrect quantity of laundry, the discussed publication proposes todesign the upper cover plate of the washing-machine as scales comprisinga display where the operator can read the correct laundry weight.Additionally, the result of the weighing operation may also be employedfor varying the program of the washing-machine, for which purpose theweighing system can be coupled with the program control of thewashing-machine. Except for these aspects, the publication does notpropose to take other actions on the program sequence or the loadingquantities.

In contrast, the arrangement of the washing-machine described by BritishPatent Application GB-2 087 438 A is such that liquid-filled weightsensors operating on a piezoelectric/resistive basis are mounted at thelower mounting points of supports of the drum and/or its container, suchsupports taking the form of hydraulic shock absorbers, for example. Theoutput signals of the weight sensors are then transmitted to a centralcontrol circuit, for example in the form of a program-controlledmicroprocessor, which is said to be capable of determining the quantityof detergent to be added.

However, it is a common problem of these known "weight-determining"washing-machines, including the machines which will be described furtherbelow, that the weight sensors, regardless of their shape and design,are always arranged either in the area of the feet of the entire housingof the washing-machine, or in the area of the hydraulic suspension ofthe lye tank or the drums, so that the hydraulic properties of theseelements are always included, or have to be included, in themeasurements. In addition, and this is a very important fact, though notmentioned at any point of the publication, the influence of the supplyhoses and in particular the rubber seal in the area of the door of thedrum is also disregarded. However, these aspects alone already causeerrors so important that--in particular if one additionally considersthe frictional influences usually dependent on the prevailingtemperatures and/or environmental conditions (wet or dry rubber seal ofthe door)--the measuring results achievable from time to time are noteven sufficiently accurate to guarantee an at least approximatedetermination of the weight of the laundry, not to speak of thedesirable metering accuracy in the gram range for the detergentquantities to be added. Finally, it has been known in connection with awashing-machine (EP 0294014 A1) to arrange weight sensors in the area ofthe resilient drum suspension, for supplying a microprocessorcontrolling the program sequence and in particular the spinningoperations of the washing-machine with signals representative of dynamicweight variations resulting from imbalance conditions occurring duringthe spinning operation. Such signals are then compared withpredetermined threshold values, and when the latter are exceeded eitherthe spinning operation is stopped, or the acceleration of the spinningmotor is interrupted for a certain period of time. Similar measures havebeen known also from CH-PS 651 602.

Generally, it can be said that when washing-machines are operated on thebasis of minicomputers or microprocessors with controlled programsequences, the sequence control has to rely on data supplied by sensorsin order to be able to control the operation of the washing-machineproperly, from the first start-up and the initial introduction of therequired water quantity, up to the final spinning operation. Suchsensors are more and more becoming the weakest element in the processingchain, and this not only because, being actual value transmitters, theyget into direct contact with the agents to be measured, but also becausethe ever progressing degree of electronic equipment in washing-machinespermits ever higher accuracies to be achieved--a requirement whichcannot, however, be met by today's actual-value transmitters. Forexample, it is already a problem with washing-machines to adjust thewater level in the drum precisely to the level determined by the programin order to ensure on the one hand that the machine does not consume toomuch water--this already for environmental reasons--and on the otherhand that the washing program will work as desired. The water levelreached at any time is usually measured with the aid of level sensors,level pick-ups or pressure cells which are exposed to the waterunilaterally. However, all these elements are connected with thedisadvantage that trouble caused by dirt, furring, or the like maydevelop especially in the area of such elements, in particular after anextended service life of the washing-machine, and in addition theactual-value information supplied by such sensors is not alwayssufficiently accurate.

Further, it is desirable for the purposes of a washing-machine that thecentral control circuit be supplied with an initial informationregarding the quantity of laundry filled into the washing-machine sothat the circuit may then compute the required water quantity, based onsuch information, control the water supply and determine, andautomatically add, the desired detergent quantities.

There is, therefore, a demand for a highly precise and, above all,robust level-measuring system for washing-machines which is capable ofsupplying data from which the computer installed in the washing-machinecan derive the necessary metering steps automatically.

Now, it is the object of the present invention to specify afilling-quantity measuring system for a washing-machine which isparticularly precise, gives reproducible measurements and which is,above all, resistant to aging and can be used universally, and which notonly determines the quantity of the laundry filled in, but supplies acentral control circuit with all actual values required for ensuringprecise program operation and proper control of the filling levels.

ADVANTAGES OF THE INVENTION

The invention provides the advantage that the highly precise measurementof all weight data of interest, which is now rendered possible by theinvention, ensures on the one hand perfect operation of thewashing-machine and the highest degree of consideration of environmentalaspects, while eliminating at the same time the need for all the otherouter sensors, level indicators, and the like previously required bysuch washing-machines.

In the case of the washing-machine according to the invention, once thelaundry has been introduced and measured exactly, the program is capableof determining not only the liquid level for the different washingprograms, but also the quantity of water to be added, by weighing thelatter. So, it is now possible to preset continuously any desired liquidlevels in the lye tank, combined with the addition of the requiredquantities of detergents of any type and origin, i.e. liquid or inpowder form, the detergent quantity added being also measured byweighing. A washing-machine operating according to the parameters of thepresent invention is, therefore, capable of cleaning laundry in aparticularly economic, and on the other hand in a particularly effectiveway, as the laundry in the washing-machine is always treated exactlywith those quantities of water and detergents which have been found togive optimum cleaning results. The invention, therefore, avoids allimaginable estimations of values which heretofore normally caused theoperators to add excessive quantities of detergents, in order to be onthe safe side, but sometimes also because they did not know thedetergent quantities actually required, or else because the quantitiesindicated, for example by the detergent manufacturers, naturally had tobe little accurate as the detergent manufacturer also had no means ofpredicting exactly the weight of the laundry in the washing-machine.

It is, therefore, regarded as a particular advantage of the presentinvention that the operator only has to inform the control circuit ofthe washing-machine at the beginning of the washing operation what sortof laundry is to be treated (white linen, colored linen, woolen clothes,or the like) and, for example, what relative degree of dirtiness has tobe considered--the rest will then be done by the washing-machine, due tothe extensive program structure provided by the programming of themachine, which is capable of allowing for even extreme items and ofoperating with high precision, thanks to the highly precise actual-valuemeasurements of all filling quantities of interest, which are ensured bythe present invention.

The invention succeeds in this respect in eliminating fully allfrictional influences which heretofore always led to non-reproducible orgenerally useless weight data, in particular due to unpredictablehysteresis effects. The use of a particular type of weight sensor is notcritical in this connection, although resistance strain gauges are apreferred choice. However, other displacement/force pickups providing acorresponding output signal representative of a weight, such aspiezoelectric systems, moving-coil systems, string balances, proximityswitches, or the like, are also imaginable.

The common decisive element of all embodiments lies in the fact that adecoupling frame is provided between the outer housing and all interiorarrangements of the washing-machine, which frame supports all mechanismsand components of the washing-machine, including the lye tank, the drum,the hydraulic supports, the door system, and so on, and which itself issuspended in the outer stationary housing via leaf springs, while theresistance strain gauges preferably used in this case are mounted on andfixed to the said leaf springs.

It being also possible, according to certain preferred embodiments ofthe invention, to implement the supply of the washing-machine systemwithout hose connections, via an air gap, using suitable funnels andfilling means, the decoupling frame remains really absolutely decoupledfrom all frictional influences which means that thanks to the advancedweighing technique (spring-leaf suspension with resistance straingauges) it is actually possible to achieve measurements with an accuracyin the gram range, even if only a quantity equal to one or twotablespoons of some agent are needed for a rinsing operation or thelike.

The resistance strain gauges employed are capable of supplying absoluteand relative measurements, with accuracies of up to five decimal pointsof a measured value. Even if one assumes an initial weight of 100 Kg orso for the decoupling frame together with all interior installations ofthe washing-machine, the output signals representative of the actualweight, which can be achieved with the aid of the present invention, areactually determined with an accuracy in the gram range, it being furtherpossible to employ circuits and converters of the known type inconnection with such resistance strain gauges for evaluating the analogsignals so obtained.

An analog-to-digital converter particularly well suited in thisconnection has been described by DE-PS 36 30 633 so that the measuringprinciple discussed there need not be explained here once more in fulldetail.

According to a preferred embodiment of the present invention, thesensors in the form of resistance strain gauges are arranged as part ofa Wheatstone bridge, and the supply voltage of the bridge is an ACvoltage, in order to avoid errors due to polarizing potentials.

In summary, it can therefore be said that the invention, while ensuringoptimum environmental protection, achieves simultaneously optimumwashing results, combined with reduced water consumption and precisemetering of the consumption of detergents, it being only necessary forthis purpose to use corresponding weight sensors and to have all agentsnecessary for carrying out a washing-process, including the hot or coldwater, automatically supplied through correspondingly controlled valvesor from a wash-in supply container comprising several chambers, ifdesired.

The features specified in the subclaims permit advantageous improvementsand further developments of the invention. A particularly advantageousdesign of the washing-machine is achieved when the decoupling frame andat least the front face of the washing-machine, including the dooropening mechanism, and the like, are designed as a single piece so thatit is no longer necessary to leave a larger gap in the outer housingaround the door opening in order to prevent the door from hittingagainst the housing in the event of more violent movements of the drum,for example during a spinning operation. Any influences on the weighingresult by the door seal as such are anyway excluded as the lye tank,which is sealed by the door, also belongs to those components of thewashing-machine which are supported by the decoupling frame and as inany case the door is not fastened to the outer housing of thewashing-machine.

BRIEF DESCRIPTION OF THE DRAWING

Certain embodiments of the invention will now be described in moredetail with reference to the drawing in which

FIG. 1 is a very diagrammatic representation of the basic structure ofone embodiment of a washing-machine according to the invention,comprising preferred embodiments of actual-weight value pickups in theform of resistance strain gauges mounted directly on the leaf springswhich support the inner decoupling frame;

FIG. 2 shows another possible embodiment of an actual-value pickup forthe weighing process;

FIG. 3 is a larger, diagrammatic representation of the actual-valuesensor in the form of a moving-coil pickup for the weight measurements;

FIG. 4 is a larger representation of a detail of a preferred embodimentof a washing-machine, where the decoupling frame comprises the frontplate of the washing-machine;

FIGS. 5 and 6 show front and side views of a metering unit which isfully decoupled from the washing-machine system which is suspended bymeans of the inner decoupling frame; and

FIGS. 7A and 7B shows one possible embodiment of a flow diagram(functional sequence) for the operation of a washing-machine accordingto the invention, with a filling-quantity measuring feature usingweighing processes.

DESCRIPTION OF THE EMBODIMENTS

The basic idea of the present invention is seen in the fact that theentire inner system of a washing-machine is decoupled relative to theouter stationary housing, which rests on a base, by means of anadditional decoupling frame and leaf-spring suspensions, thus renderingit independent in particular from frictional influences and enablingincreases or decreases of the weight in the area of the drum and/or ofthe lye tank to be determined by suitable weight-measuring sensors,preferably in the form of resistance strain gauges, arranged on the leafsprings or coacting with the latter.

Considering the very high precision and resolution of resistance straingauges that can be achieved today, this arrangement, in combination withthe leaf-spring suspension, allows all processes of the washing-machinerelating to filling quantities, including in particular the addition ofdetergents, to be controlled automatically.

The washing-machine 10 illustrated very diagrammatically in FIG. 1comprises an outer housing 11 resting in stationary relationship on astationary support 30, for example by feet 15a, 15b. Inside the housing,there can be seen a carrier 31, which will be described hereafter asdecoupling frame and which may, generally, have any desired shape. Thecarrier 31 as illustrated in FIG. 1 has the shape of a closed box, thedepth of which may however be very small, so that such a decouplingframe 31 can be produced at low cost by welding together rails orprofiled sections.

This inner carrier, or decoupling frame 31 then carries all the othercomponents of the washing-machine or, to say it in other words, theentire washing-machine system, i.e. a drum 12a in its lye tank 12, thelatter being in its turn supported inside the decoupling frame 31 in asuitable manner, for example via upper suspension springs 13a, 13b andlower supporting/damping elements 14a, 14b. The particular design of themeans by which the drum 12a is suspended and supported in and on the lyetank 12 is of minor importance. For example, such supporting means maywell have the design of a suitable star-shaped mounting bracket by whichthe drum 12a may be mounted unilaterally in the lye tank.

The essential feature is seen in the fact that the carrier or decouplingframe 31 supporting the whole washing-machine system with all itsnecessary components, i.e. drive motor, belt pulleys, door for the drumwith seal, and the like, is suspended, preferably only by one side,within the outer housing 11, preferably by means of leaf springs fixedat their two ends. In FIG. 1, the leaf springs 17a, 17b supporting andcarrying the decoupling frame 31 are arranged between the neighboringleft side walls--as viewed in FIG. 1--of the stationary outer housing 11and the decoupling frame 31, and have both ends fixed, for example bywelding, at the outer housing 11 and the decoupling frame 31,respectively. Consequently, the leaf springs 17a, 17b are fixed at bothends so that they will get distorted only very slightly, even whenheavily loaded, as can be seen best in the representation of FIG. 2which shows once more a detail view of the respective neighboring wallportions of the outer housing 11 and the inner decoupling frame 31. FIG.2 further shows one possible special shape of the leaf springs,comprising upper and lower notches at predetermined points so that theleaf spring will react to variations of weight by distortions in thearea of these notches, which distortions can be measured particularlyefficiently by resistance strain gauges 18a, 18b which can be seen inthe drawing above the notches 16. As an alternative solution, therepresentation of FIG. 2 further shows another weight-measuringarrangement 19 which may have the design described in more detail inFIG. 3 and which may consist, for example, of a differential coil 19'comprising two coil windings 23a, 23b separated by a center tap 24, anda ferrite core 25 which may occupy a central or zero position at thebeginning of the measurement and which is driven by the movement towhich the decoupling frame 31 is subjected by any variations in weight.The two outer connections 26a, 26b of the moving coil can then besupplied with a rf voltage, and the electric detuning resulting from thechanges in position of the ferrite core 25 inside the moving coil thenleads to variations of the analog signal which can be converted, just asin the case of the resistance strain gauges, by means ofanalog-to-digital converters and can then be supplied directly to amicroprocessor for further processing.

The structure of a washing-machine embodying the basic principle of theinvention is shown in detail in FIG. 4. In the case of this embodiment,the stationary outer housing 11' can be completely open at the front,i.e. at the right in FIG. 4 where the door of the washing-machine isarranged, while the remaining outer wall portions, including the bottom11a', the rear wall 11b', the upper top 11c' and the side walls notshown in the drawing are all in place. The forwardly open rectangularshape then encloses the decoupling frame 31, which may well do withoutany side or top walls and which may only consist of the portionsillustrated in FIG. 4, i.e. a rear wall portion 31b', a bottom wallportion 31a' and, in this case, a front 31b' replacing the missing frontwall of the stationary outer housing 11'. One obtains in this manner aframe which is simply open at the top and which supports the wholewashing-machine system including the drum.

Regarding now FIG. 4, one can see the inner drum 12a', the drum tank 12'housing the drum 12a' and being supported in the decoupling frame 31' ina suitable manner not shown in detail, further a first drive motor 32driving the drum via a belt 33, a lye pump 34 and a door mechanism 35.

The door seals the upper filling opening 36 of the lye tank 12' in asuitable manner, for example by means of a rubber compression seal 37,and is optionally fastened directly to the lye tank 12' or, if thisshould be desired or be more advantageous, in the usual manner to thevisible front wall of the washing-machine, i.e. to the front wall 31b'of the inner decoupling frame 31'. This latter solution is also possiblewithout any problems because the lye tank 12' is seated inside thedecoupling frame 31' and mounted to the latter, in resilientrelationship if required, so that the rubber seal 37 is subjected torelative movements during operation of the washing-machine, similarly tothe conditions prevailing in usual washing-machines. On the other hand,however, it is ensured that these conditions do not lead to frictionalinfluences on the measurements as--as has been explained before--it isthe whole decoupling frame 31' which is suspended resiliently relativeto the stationary outer housing 11', by means of the leaf springs 17a'and 17b' which are visible in this representation, too. Given the factthat the weight measurements are performed only on these leaf springs,any additional hose connections or means for introducing water ordetergents, washing powder, fabric softeners, or the like, are not inany way disturbing in this connection, all these agents being washed inthrough a stationary wash-in or detergent container 38, which may alsohave several chambers, via an air gap, as can be seen best in FIGS. 5and 6. As compared to this, the relative movements between the outerstationary housing 11' and the decoupling frame 31' are extremelysmall--to give a numerical value, which is however not meant to limitthe invention, the displacement may amount to only 0.5 mm per 300 Kg ofchange in weight, a positional change which is nevertheless sufficientto permit a measuring accuracy in the before-mentioned gram range, dueto the extreme sensitivity of modern resistance strain gauge systems.

It goes without saying that the front wall of the washing-machine andother parts belonging to the decoupling frame 31' are decoupled relativeto the stationary housing 11', for example in the way illustrated in thetransitional area 39 in FIG. 4, where neighboring wall edges adjoin eachother in the form of a gap-type labyrinth seal.

If an open gap at the front is to be avoided, then it may also berecommendable to design the transition between the two adjoining walledges in the manner illustrated by the detail 39'.

As regards the drain hose connected to the lye pump 34--a strainer is ofcourse arranged inside the decoupling frame 31'--measuring problems canbe avoided by running it in the form of a big loop, for example in theway illustrated for the supply hose in FIG. 4--a measure which as suchis not necessary in the present case.

According to FIG. 5, a funnel-like protuberance or extension 40 of thelye tank 12' may be designed in such a way that the supply of water ordetergents from the wash-in or detergent container 38 is effected via anair gap 41, defined by the distance between the upper open end of thefunnel 40 at the lye container and a tapering outlet portion 38a of thecontainer. The container may also comprise several chambers, asillustrated in FIG. 6, i.e. a first chamber 38a and a second or thirdand forth chamber 38b, etc., it being also possible to have thedetergent washed in by the valve-controlled fresh water supply, ifpredetermined detergent quantities are filled into the wash-in anddetergent container 38 from a larger supply container not shown in thedrawing. This latter operation may be effected with the aid of any sortof metering arrangement, in the case of detergents in powder form forexample by the use of a worm conveyor, or in the case of liquids by anyother of the known highly precise metering arrangements. Alternatively,it is of course also possible to provide a supply container, preferablyof a multi-chamber design, containing larger quantities of differentwashing ingredients, similar to the wash-in container 38, as a unitseparate from the fresh water supply, in which case the transfer of thedetergent quantities may also be effected by similar funnel arrangementswith air gaps, whereas the supply of the respective detergent can bestopped, for example by means of a valve control, when the weighingarrangement signals that a pre-calculated quantity is reached. In thiscase, no separate metering arrangements are required for detergents inliquid or powder form. Such a detergent supply is also preferred becausein most cases the lye container is anyway open towards the top so thatthe addition of washing agents, at different stages or positions in thewashing cycle, can be realized most simply by a weight-dependent system.

It should be noted in this connection that the basic principle describedabove lends itself for application in the most variant forms in othermachines for the treatment of laundry, for example in dryers where thedecrease in relative humidity can be determined without any problem byweight measurements. In this case, one preferably proceeds in such a waythat the dryer is caused to perform weight measurements at predeterminedpoints in time--all inner components of the dryer are of courseseparated from the stationary outer housing in the described manner, bya decoupling frame--and that the degree of dryness is then derived fromthe curve shape of the relative decrease in weight, which approachesasymptotically a threshold value--a process which can be handled withoutany problem by the central control circuit (microprocessor), providedcorresponding predetermined curve shapes have been stored. It is thenalso possible without any problem to determine those points in the knowncurve shapes where the degrees of dryness described as "completely dry"or "ready for ironing" have been reached.

Another advantageous application of the present invention is seen in thefact that the weight measurements also permit imbalance phenomena, whichmay occur during spinning operations in washing-machines, to be detectedif certain threshold values are exceeded, and to initiate suitablemeasures for remedying such phenomena. The central control unit(microprocessor or minicomputer) determines to this end if the dynamicweight variations signaled by the resistance strain gauges during thespinning operations exceed certain threshold values, latter which can befixed without any problem by previous measurements. If so, it isrecommendable to either stop the spinning operation and/or to distributethe laundry more efficiently in the drum, which can be achieved by shortrotating cycles of the drum with intermediate short reversing cycles,whereafter the spinning process can be re-started, and/or to emit analarm if no improved conditions are obtained following a certain numberof repetitions of this process.

Given the fact that the process of influencing spinning operations,including dynamic variations of weight, has been described as such bythe before-mentioned publications (DE-OS 34 13 967, GB 20 87 438) itneed not be described here once more in full detail.

The operational sequence of an entire washing-machine control may thenbe designed in the manner of the embodiment illustrated in FIGS. 7A and7B by way of a flow diagram (functional sequence). According to thisdiagram, switching-on of the machine at the functional block 1 firstleads to the usual status checkup, i.e. initialization of the values andreset at the functional block II.

Thereafter, an indication "ready to be filled" appears, and the laundryis filled in by the operator. At this point, relevant informationregarding the type of laundry, for example white linen, wool or coloredlinen, or the like, or relating to the degree of dirtiness, may beprovided, if desired and if not implied by the selected program. Uponcompletion of the filling operation, a first weighing process (1stweighting process) is initiated for determining the weight of thelaundry. The laundry weight so determined, the internal informationregarding the type of laundry and another internal information relatingfor example to the desired program, are then employed by themicroprocessor for calculating the desired water level, making use ifrequired of values stored in an EPROM, for example, and for actuatingthe water supply control. At the same time, the microprocessor maydetermine the quantity of detergent required for a perfect washingoperation. The desired detergent quantity can then be taken from adetergent supply which must be replenished occasionally.

The water supply control then opens the electromagnetic solenoid valvefor the water supply, and the water quantity by which the desired waterlevel can be reached, is determined by a differential measuring process.

Once the desired water quantity has been filled in, the supply valve isclosed and the washing program is controlled as usual. There is nonecessity to describe the functional sequence of FIGS. 7A and 7B in moredetail as the lettering of the functional blocks representing theindividual steps of the program describes the latter with sufficientclarity.

It is understood that the employed components or the entire centralcontrol, especially as regards the electronic control, may be based onanalog, digital or hybrid technology, or may comprise, in fully orpartially integrated form, corresponding portions of programcontrolleddigital systems, for example of the employed microprocessor,microcomputer, or the like. Another preferred application of the presentinvention is seen in the fact that the weighing system anyway providedcan be used also in a washing-machine of the described type for managingthe imbalance problem. Heretofore, any imbalance phenomena provoked inthe drum by the high rotary speed during the spinning operation, as aresult of some irregular distribution of the content of the drum, had tobe determined either by mechanical switches or by electric measurementsof the motor current, which indicated the existence of imbalance troublein the drum connected to the electric drive motor, for example bypulsation of the current. However, such measuring methods, being alwaysindirect methods, are always connected with corresponding inaccuracies.

By including measurements of forces, effected by means of suitablescales, it is now possible to determine directly the deflection forcescaused by a rotating drum in the presence of imbalance conditions, andto take corresponding remedial measures when predetermined thresholdvalues are exceeded, which measures may for example include stopping ofthe machine, re-starting or reversing of the direction of motion, inorder to achieve better distribution of the content in the drum, and thelike.

It should be finally noted that the claims and in particular the mainclaim are intended as attempts at formulating the invention, withoutcomprehensive knowledge of the state of the prior art, so that theyshould not be interpreted as limiting the invention. Rather, it isunderstood that all the features described in the specification, theclaims and the drawing may be regarded as essential to the inventioneither individually or in any combination thereof and may also bespecified in the claims, and that the features contained in the mainclaim may also be reduced.

I claim:
 1. In a machine for treating laundry, said machine being of thetype including a drum mounted for rotation inside a housing resting on astationary supporting surface, and weight sensor means responsive tovariations of the weight of the drum, for at least one of (i)measurement of the weight of the laundry, (ii) subsequent determinationof the quantities of treatment agents to be filled in (water,detergents, or the like), (iii) determining the relative humiditycontent of the laundry in dryers, and (iv) detecting and removingimbalance conditions occurring during spinning operations inwashing-machines, or the like, the improvement comprising:a decouplingframe arranged at least partially within the housing and in spacedrelationship thereto, substantially the entire inner system of themachine being mounted to the decoupling frame, and means for resilientlymounting the decoupling frame in the housing, at least one of the weightsensor means being responsive to relative movements between thedecoupling frame and the housing caused by weight variations occurringin the decoupling frame.
 2. A machine for treating laundry according toclaim 1, wherein the decoupling frame is suspended on the housing bymeans of spaced leaf springs.
 3. A machine for treating laundryaccording to claim 1, wherein the decoupling frame is supported in thehousing only on one side, by means of leaf springs arranged at differentvertical heights.
 4. A machine for treating laundry according to claim3, wherein the at least one weight sensor means is a resistance straingauge arranged on one of the leaf springs.
 5. A machine for treatinglaundry according to claim 4 wherein said at least one weight sensormeans are arranged on each of the leaf springs.
 6. A machine fortreating laundry according to claim 2, wherein at least one of theweight sensor means is a resistance strain gauge arranged on one of theleaf springs.
 7. A machine for treating laundry according to claim 6wherein said at least one weight sensor means are arranged on each ofthe leaf springs.
 8. A machine for treating laundry according to claim7, wherein the at least one weight sensor means is one of anelectromechanical transducer, piezoelectric pressure pickup, amoving-coil arrangements, a string balance, and an inductive orcapacitive proximity sensor.
 9. A machine for treating laundry accordingto claim 1, wherein the decoupling frame is a closed rectangular frameconstituted by profiled sections, in which a lye tank is suspended in anelastically resilient way.
 10. A machine for the treatment of laundryaccording to claim 1, wherein the decoupling frame is an open structureof carrier elements on which the components of the machine are suspendedor supported.
 11. A machine for treating laundry, according to claim 1wherein the decoupling frame comprises at least a rear wall, a bottomwall, and a front wall, the full surface of which is inserted into anopen front area of the housing in such a way that clearance is obtainedon all sides.
 12. A machine for treating laundry, according to claim 1wherein a door providing access to a drum is fastened to one of: (a) alye tank enclosing the drum; and (b) a machine front formed by thedecoupling frame, and the door comprises a rubber seal sealing at leastone of the lye container and the drum to the outside.
 13. A machine fortreating laundry according to claim 1, wherein at least one of freshwater and detergent to be washed in by the water are supplied from astationary detergent container, which is mounted on the housing, via anair gap to a funnel-structure coupled to the decoupling frame.
 14. Amachine for treating laundry according to claim 13, further comprisingmeans for determining the quantity of detergent to add to the machine inresponse to said at least one weight sensor means and means forintroducing the detergent, including a mechanical metering device.
 15. Amachine for treating laundry according to claim 1, wherein separate(multi-chamber) detergent containers are provided which are controlledby a central control means to supply detergents, washing powder, fabricsofteners, and the like, to a funnel structure mounted to the decouplingframe, via an air gap, until the actual value determined by a weightmeasurement performed by said at least one weight sensor conforms to apredetermined detergent quantity, whereupon the further supply isstopped.
 16. A machine for treating laundry according to claim 1,wherein during supply of hot drying air to the drum the relativevariation in weight resulting from the evaporation of water is measuredsuccessively by measurements performed at predetermined intervals,conclusions as to the remaining humidity content in the laundry beingdried are derived from the curve shape of the degree of evaporation, andthe drying process is interrupted when a predetermined desired value isreached.
 17. A machine for treating laundry according to claim 1,wherein imbalance conditions are detected on the basis of dynamicvariations in weight and an ongoing spinning operation is interruptedand/or the distribution of the laundry in the drum is improved by shortdrum rotation cycles, including reversing movements, when a comparisonwith pre determined threshold values shows that the latter have beenexceeded, whereupon the spinning process is restarted and/or an alarm isemitted.